The Israeli military announced on Sunday that it had discovered a tunnel leading from Gaza into Israel that it said could have been used for an attack against Israeli soldiers or civilians.

In response to the discovery, the military said it had suspended the flow of building materials to the private sector in Gaza, a Palestinian coastal enclave.Maj. Gen. Sami Turgeman, Israel’s Southern Command chief, said the freeze was ordered because Hamas, the Islamic militant group that controls Gaza, had been using construction materials approved by Israel for civilian purposes to build tunnels like the one discovered recently.